<div data-field="root">
  <input data-field="input" type="text"></input>
  <button data-field="button"></button>
  <a data-field="anchor"></a>
  <button data-field="buttonWidget"></button>
  <button data-field="buttonGwtElement"></button>
  <button data-field="noFieldButton"></button>
  <button data-field="privateHandler"></button>
</div>